In a sonar, an audio beam is a beam directed in the direction of a “contact” in order to be able to hear the noise emanating from this contact. This solution is satisfactory to the extent that, for steady noise, the operator can effectually listen to all noteworthy contacts sequentially. In the case of panoramic surveillance of impulsive noise, a simple solution consists in allowing the operator to listen to an impulsive noise after storing it (the decision to store it having been taken according to azimuth, spectrum, duration, etc. criteria). This solution is to be adopted when the operator performs additional analysis. However, in this solution, the audio signals are not used to sort contacts. This solution must thus be complemented by another audio system allowing such sorting. Given that impulsive noises, by definition, last only a short time, a panoramic audio system is required that is capable of hearing noises from the entire horizon and this, of course, without losing the advantage of beamforming. This need is all the more pressing in a combat situation, notably for a submarine, that must be able to rapidly distinguish between an aircraft passing overhead and a torpedo coming towards it.
An audio device that meets this need for panoramic listening to sources of noise in real-time is hitherto unknown.